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Forum nameTurbo/Nitrous Tech
Topic subjecthow high would you boost this engine...
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=104676
104676, how high would you boost this engine...
Posted by kevox, Nov-16-08 08:38 PM
Alright so here's what will all be in and running by this time next month...
Main Upgrades
3-angle valve job + general machining of the block
Crower Stage 2 Turbo Ground Camshafts
Eagle Rods
Hahn 20g turbo w/ Intercooler
Hahn 3” Downpipe + 2.25” Magnaflow High-Flow Cat + 2.5” Catback Exhaust
Megasquirt Fuel Management ECU
Southbend Stage 3 Clutch
Turbonetics Exhaust Manifold
Wiseco 8.8:1 Pistons .020 over



Supporting Upgrades
557cc Fuel Injectors
AEM Adjustable Fuel Pressure Regulator
ARP Head Studs
ARP Main Studs
ARP Rod Bolts
Autometer Sport-Comp series gauges (5 gauges in all)
Crower Valve Springs
Crower Valve Retainers
EGR Blockoff
Fidanza Adjustable Cam Gears
Greddy Electronic Boost Controller w/ remote High-Low boost switch
GReddy Type-RS Blow-Off Valve
Iraggi 200A Alternator
Melling High Volume Oil Pump
MSD Ignition Coil
MSD Spark Plug Wires
OEM Timing Belt
Prothane Engine Mount inserts
SS Valves
Tanabe Front Underbrace
Topline Lifters + Rockers
Unorthodox Racing underdrive pulley
Wideband 02 sensor
Walbro High-Volume Fuel Pump


My question is simple: how high, given a good tune, do you think this engine can be boosted for daily driving? I'm hoping it'll love 20psi (again, assuming there is a GOOD tune!) but I'm planning on restricting it to 16psi just to play it safe. Then again the thought of that extra 4psi is really tantalizing, lol....what would you guys feel safe running this 420a at?
104677, RE: how high would you boost this engine...
Posted by halfasss101, Nov-16-08 10:13 PM
Everything you will have looks good to me to boost over 20 no problem. Looks to me like your weakest link will be your clutch. 20 psi would be ok on that clutch. I think you would have also been better off with the stage 2 crower N/A cams. I haven't heard too many good things about the turbo grind. I will have the N/A cams in mine. PT cruiser rockers and lifters would have been a better choice i think. At 20psi on a good tune, you should be low 300's at the wheels. Running in the 12 sec range no problem. Looks like a pretty good setup to me.
104678, RE: how high would you boost this engine...
Posted by Flipboi89, Nov-17-08 02:43 AM
This is not your dd right? lol
104680, RE: how high would you boost this engine...
Posted by Slo2g, Nov-17-08 01:25 PM
On 20psi it should be higher than low 300's. Just my opinion because T put down 400 on 22psi. The CROWER turbo cams are great cams for a turbocharged application. The CRANE turbo cams suck ass.

edit: And Thuras turbo was a S20g.
104681, RE: how high would you boost this engine...
Posted by halfasss101, Nov-17-08 01:51 PM
Oh yes, I was thinking of the crane cams for some reason. Crower's turbo cams are better. Everyone has different results with their setups even if they are similar. Pretty much depends on the tune. Some people here have told me that at the 28 psi i'll be running i might get 400 if i'm lucky. I have a built head (minus oversized valves :( ) also with crower stage 2 N/A cams and adjustable gears. I might turn the boost up to 30-32 depending on what i dyno at. My goal is 500, but whether I'll get there without a 50, i do not know for sure. I'll just have to keep tweaking A/F's til i find the best one.
104682, RE: how high would you boost this engine...
Posted by bullettdsm, Nov-17-08 09:34 PM
Just trying to follow along a little here. You guys aren't using boost pressure as a power level determinator, right? Unless you are comparing relatively close set-ups with the same turbo, boost does not equal power (heh heh, that sounds a little funny), your set-up does. 20 psi on a 14b does not equal 20 psi on a 42r.

104684, RE: how high would you boost this engine...
Posted by DarkOne, Nov-18-08 03:26 AM
Regardless of boost pressure, after around 400wHP, you'll probably start lifting the head. The 7/16" ARP head studs start to stretch near those cylinder pressures, from what I have heard from people in the know.
104690, RE: how high would you boost this engine...
Posted by kevox, Nov-18-08 05:48 AM
Originally posted by DarkOne
Regardless of boost pressure, after around 400wHP, you'll probably start lifting the head. The 7/16" ARP head studs start to stretch near those cylinder pressures, from what I have heard from people in the know.


Dang really? I thought ARP were the best studs available? What kinda studs are people using with 400+HP? I highly doubt I'll get close enough to 400 to need to worry about this but knowledge is power!
104697, RE: how high would you boost this engine...
Posted by bullettdsm, Nov-18-08 11:32 AM
Originally posted by DarkOne
Regardless of boost pressure, after around 400wHP, you'll probably start lifting the head. The 7/16" ARP head studs start to stretch near those cylinder pressures, from what I have heard from people in the know.

Well....this is kinda up in the air for me. Its a subject I have been following and researching. I have every intention of finding out soon. Its almost the same as the early arguement about the 1g heads lifting on stock bolts at around 300whp.

FWIW, there has certainly been a concensus that the heads do lift at around 400whp. I'm not quite there (as a believer) yet.

The funny thing is I just found out today that a friend of mine came up with over 500whp (513whp (?) I can't remember it was in the teens) on his Neon. Yeah, a little different head set-up but close for comparison.

Meh, food for thought.

104707, RE: how high would you boost this engine...
Posted by DarkOne, Nov-20-08 08:43 AM
Originally posted by bullettdsm
I'm not quite there (as a believer) yet.


I'm simply parroting what Bill Hahn learned from his experience. I'm South of 400, so I can't verify it with personal experience, but he's the kinda guy I'm willing to take at his word.
104708, RE: how high would you boost this engine...
Posted by bullettdsm, Nov-20-08 10:42 AM
Originally posted by DarkOne
Originally posted by bullettdsm I'm not quite there (as a believer) yet.
I'm simply parroting what Bill Hahn learned from his experience.

Hmm, Hahn, who's that, lol?

No doubt the theory has a basis in fact.

104689, RE: how high would you boost this engine...
Posted by kevox, Nov-18-08 05:46 AM
Originally posted by bullettdsm
Just trying to follow along a little here. You guys aren't using boost pressure as a power level determinator, right? Unless you are comparing relatively close set-ups with the same turbo, boost does not equal power (heh heh, that sounds a little funny), your set-up does. 20 psi on a 14b does not equal 20 psi on a 42r.


I personally am not. I realize there is no way for anyone to know how much hp my engine will make so I'm going to the next variable - finding out how much boost I should be able to run safely!
104705, RE: how high would you boost this engine...
Posted by Corbin, Nov-19-08 07:42 PM
If you choose a common static fuel pressure around 45 psi, you might be at the top end of those injectors by 20 psi boost. It might be wise to log your duty cycle when you get up to that boost.

Corbin

'95 ESI-T
Now with more power and fewer leaks



Gimme fuel...Gimme fire...Gimme that which I desire
104706, RE: how high would you boost this engine...
Posted by kevox, Nov-20-08 01:14 AM
Originally posted by Corbin
If you choose a common static fuel pressure around 45 psi, you might be at the top end of those injectors by 20 psi boost. It might be wise to log your duty cycle when you get up to that boost. Corbin '95 ESI-T Now with more power and fewer leaks Gimme fuel...Gimme fire...Gimme that which I desire

Really? That sucks to hear - I thought 557cc's would be all I'd need and then some...hopefully they don't max out at 20psi! I'll leave this note with my mechanic for sure....
104698, RE: how high would you boost this engine...
Posted by Slo2g, Nov-18-08 11:33 AM
Originally posted by bullettdsm
Just trying to follow along a little here. You guys aren't using boost pressure as a power level determinator, right? Unless you are comparing relatively close set-ups with the same turbo, boost does not equal power (heh heh, that sounds a little funny), your set-up does. 20 psi on a 14b does not equal 20 psi on a 42r.


Nope, I'm not either Mark, Just stating that T put down around 400whp with a similar setup. I believe he had portfueler though and not MSnS. Along with some other different things I'm sure.